The Sam Mitchel Herbarium of Fungi

by Graham on December 30, 2010

Recently James, Ashley, and I got the opportunity to visit The Sam Mitchel Herbarium of Fungi at The Denver Botanic Gardens. The herbarium is located at the York St. Gardens in the Capitol Hill district of downtown Denver. Ever since I was a child, I have loved to visit this place. The grounds are very extensive and cover many different landscaping techniques. But one of my favorite places is the impressive glass conservatory that seems to tower over the gardens. It is hard to miss. When you walk inside this giant glass bubble, the first thing you notice is how wonderful the atmosphere is, and all around you are the most interesting plants. Many visitors to the Denver Botanic Gardens are unaware, however, that many different types of fungi are just below their feet…

Ashley and I were running a little late. Unfortunately it still took us a while to find the staircase we were told about, and after several locked doors, looks from various confused garden staff, and walking in concentric circles, we honed in on the basement door. It then took us several more minutes to navigate our way through various hallways, until we came upon a sign next to a door that read, ‘Research & Herbarium’. I was thinking, “This place is awesome already”. We followed the signs for fungi, which was really easy for us. To me, it was like they put up signs that said ‘free ice cream, this way’ because I was resisting the urge to run down the quiet hallways. A sure sign of the truly obsessed. Finally we heard the familiar voices of James and Ellen. Ellen Jacobson is an absolutely wonderful woman whom we first met through the Colorado Mycological Society. She has been a long time member of CMS and is an indespensible resource on all things fungi… and other things too! She volunteers her time at the herbarium, helping Vera Evenson (author of Colorado Mushrooms) and others indentify and file all sorts of different fungi. In fact, The Sam Mitchel Herbarium of Fungi is the most complete collection in the Rocky Mountain Region preserving 22,000 specimens, covering 300 genera and 2,500 species. The storage system is pretty state of the art. Huge hanging walls of cabinets are suspended from the ceiling. Each set is on a track, and they move together and apart with motors to create a hallway between them. Inside the cabinets are many white boxes that house the dried samples of the mushroom species. Each has a card inside that describes the location found, date, collector, and any other information pertinent to the specific sample. These samples are all categorized according to their relationship to each other. The Sam Mitchel Herbarium of Fungi is one of the only herbariums of fungi that stores their samples in this manner. Most store them in alphabetical order, which doesn’t make it as easy to find the exact specimen you are looking for. Here, it is very simple to find a specific species because every type of fungi in the case you are looking at are all related to each other. The only downside to this method of categorizing the fungi is that if a species is renamed into a different group, usually due to the recent genetic mapping of the mushroom genome, the specimens in question must be refiled. Ellen said this happens quite often as she pointed to a stack of cards and boxes waiting to be refiled. It is a constant battle. There were also about a hundred books on fungi in their library whose shelves bordered the walls. One Ellen showed us in particular was the original log started by Sam Mitchel. On the first page, she showed us the very first mushroom submitted to the herbarium in 1964. The binding had completely worn away, and it was amazing to see how far the herbarium has come in the past 45 years. They are now working on entering all of this data into the computer which will make accessing the herbarium records much, much easier. But they still use the old method of storing information that Sam came up with. Each new specimen still gets a paper card inside its own preservation box, still written by hand. It was an amazing process to witness. While looking through several cases of specimens, I came upon a box with a fungus inside that I had never heard of: Battarrea stevenii. Because it is a puffball-like fungus (a gasteroid fungi) , it lives in very hot and arid conditions. But what I found most intriguing was its over 2 foot long, very fibrous stem that Ellen explained is almost completely buried in the ground. This is so they have a ‘tap root’ that allows them to access water very deep underground. How interesting is that? We would like to thank Ellen Jacobson for taking time out of her busy schedule to show us around, and the Denver Botanic Gardens for letting us visit. That’s all for now!